Detection and Removal of Sample Matrix Effects in Agrochemical Immunoassays

With the completion of the initial development of assays for many of
the most important agrochemicals, there has been an increased focus
on actual applications of agrochemical immunoassays to food and
environmental matrices. A major prerequisite to assay utilization has
been the need to identify and remove matrix interferences, which may
result in I residue-free samples appearing positive, or else samples
containing residues appearing negative; or 2. changes in the sensitivity
of residue detection, from either or both shins in the assay absorbance
values in the absence of pesticide or in the standard curve, Matrix:
effects are best detected by analysis of spikes of pesticide standards
into a solvent extract of pesticide-free matrix and comparison of this
concentration response curve with that obtained using standards
prepared in solvent alone. A number of approaches to the removal of
matrix interference is reviewed, with particular reference to examples
from the analyses of insecticide residues in plant-derived foods,
including grain and fruit products.